Don’t know if this idea is to the scale of the other ones, but I have always wanted to do build a dog collar GPS tracker. I know there are a lot of GPS loggers out there for pets, but I was thinking of an actual tracker that sends coordinates back to some server and can be displayed on a mobile device so you could track down a lost pet. Also thought about incorporating something like Sparkfun’s Wake on Shake board (https://www.sparkfun.com/products/11447) to try and conserve battery life. The limiting factor is the range of the transmitter attached to your pet, but perhaps the goal would be that you could also track your pet by using receivers in other people’s homes (i.e. other people with the same pet tracker).

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